UXO detection using small loop TEM method

Abstract

Unexploded ordnance (UXO) investigation is mainly carried out by the magnetic exploration. However, in this paper, the transient electromagnetic (TEM) method was used in order to detect UXO more accurately. Although the TEM method is usually used for deep sounding of mineral exploration, we used small loop TEM method to detect buried UXO. In order to understand the characteristics of the small loop TEM method, many experiments using small empty cans were carried out at Ito Campus in Kyushu University and a lot of features were discovered. For example, if the size of loop becomes smaller, the penetration depth becomes smaller. These results showed that the small loop TEM was applicable to UXO investigation. Based on these results, the test survey to detect the imitation UXOs using 180×180-cm-square loop was carried out. In this field experiment, there are various kinds of imitation UXOs, but all of the UXOs were detected. As a result, it was found that UXO detection by small loop TEM method is effective compared to magnetic method. Moreover, the small loop TEM method could narrow the range of UXO location to the size of 30×30cm-square.